/Engine/Source/Runtime/Core/Public/GenericPlatform/GenericPlatformMath.h
Converts a double to nearest int64 with ties rounding to nearest even May incur a performance penalty. Asserts on platforms that do not support this mode.
The 64-bit integer closest to 'F', with ties going to the nearest even number
static int64 RoundToNearestTiesToEven ( double F )